You’ve decided you want to count people: perhaps to monitor occupancy or calculate sales conversion. But which type of person counting system to choose? There are several options, the most common being:
- video person counting,
- thermal sensors,
- infra-red beams,
- hand-held tally counters.
Which you choose depends on your priorities, which will
- Directional or non-directional
- Technical Support
- Risk-Free Trial
The best performing systems achieve over 98% accuracy. Make sure though that the accuracy quoted on the manufacturers’ web sites is not just that for perfect conditions. Will the system meet your accuracy needs in your specific environment?
The most accurate systems are the video person counters. Here software analyses CCTV pictures and detects people crossing a counting zone. These systems can exceed 98% accuracy.
Next are the thermal sensors. Positioned above an entrance, they identify people by meaasuring their body heat. Quoted accuracies are between 96 and 98%. Accuracy, though, can be affected by the ambient temperature within the counting area being above or below a certain value. Low ceilings can also reduce the accuracy.
With infra-red beam systems, a sensor sends a beam to a reflector on the the opposite side of the doorway. When someone passes through, the beam breaks and a person is counted. These were in demand some years ago – now managers generally demand a higher accuracy and more comprehensive information to be collected. Additionally, accuracy tends to decrease with wide or usy entrances. If two people cross a beam together, for instance, only one count will be recorded. Direct sunlight onto the beam will also affect the system. Difficult conditions can bring accuracy down to 80%.
Hand-held tally counters are the least sophisticated of solutions. A person stands clicking the tally counter whenever anyone passes through the entrance. This may be acceptable for a one-off person counting excercise, but is obviously unsuited to continuous monitoring. Accuracy depends on the people holding the tally counters. Tally counters were once used in nightclubs and bars to monitor occupancy, but are now being replaced by automatic counting systems.
How easy is it to confirm the accuracy? With video counting systems you can watch the video to confirm the counts are accurate.
Check that your chosen solution is configurable for all the different situations in which you want to count, not only now but for possible future applications. Find out if there is any limit to the size of the people-counting systems you are considering. Can they be easily scaled up for future premises and locations? Will you want to integrate your people counts with your point-of-sale system. Can the counting system also be used for queue monitoring or mapping hotspots of most visited areas?
4. Directional or Non-Directional
Do you need to count people going in and out? The video and thermal counters do this automatically. Some infra-red beam systems rely on you dividing the count by two, although the more expensive beam counters are directional.
Do you need direct access to your data? How often? Some companies keep hold of your data and just send you reports. Others give you full access to all data so you can analyse it as you wish.
Consider also the time interval over which you want to count. Do you require the count per week, per day, per hour, per half-hour, in real-time?
If you want to see your own data – in what format do you want it? MySQL, xml, text…?
How is the data distributed: centrally at a head office PC, locally, or both? Can authorised users grab it at any time from anywhere in the world?
Just some of the questions you need to be asking yourself when specifying a system.
How much is a system going to cost? Consider initial cost, future expansion, installation, technical support, any on-going charges.
The cheapest option is the hand-held tally counter but this is not suitable for detailed analysis. Also, you need to take into account the cost of employing someone to stand there clicking the counter all day.
Next cheapest is in the non-directional infra-red beam system, followed by the directional beam counters.
The most expensive systems tend to be the thermal imaging. Like the video counters, they have installation costs. However, the thermal counter has a lower field view than video counters and you may need more thermal units to cover the same width of entrance or counting zone.
7. Technical Support
Ask your potential suppliers about their technical support policy. Make sure you will receive after-sales help should you need it.
8. Risk-Free Trial System
Finally, whichever system from whichever manufacturer you choose you should ask for a trial installation to check it suits your requirements. Your chosen supplier should be happy to arrange this. So a retail chain might ask for the system to installed in just one shop before rolling out to the rest of the chain. This way you can be confident you are making the right decision before committing widescale installation.